Business Sours on China

BEIJING—China's relationship with foreign companies is starting to sour, as tougher government policies and intensifying domestic competition combine to make one of the world's most important markets less friendly to multinationals.

Interviews with executives, lawyers, and consultants with long experience in China point to developments they say are making it much harder for many foreign companies to succeed. They say the changes suggest Beijing is reassessing China's long-standing emphasis on opening its economy to foreign...